Lifting jack



Dec. 27, 1927. 1,653,720

G. F. McCAUGHEY LIFTING JACK Filed Oct. 11. 1926 l IM.

Panarea nec. 21, 1927.

UNITED STATES `PATENT OFFICE.

GLEN F. IcCAUGHEY, 0F RACINE, WISCONSIN, ASSIGNOR T0 WALKER MANUFACTUR- ING COMPANY, 0F RACINE, WISCONSIN, A CORPORATION OF WISCONSIIL LII'TING JACK.

Application tiled October 11, 1926. Serial No. 140,849.

This invention relates to the class of devices known as lifting jacks, and more p articularly to a jack of the double extension t e, designed to have an exceptmnally long ligt): in proportion to its size and helght when in lowered or collapsed position.

Whilethe're 'are innumerable uses for such a jack, it is especially designed for use with the large size or balloon tires. For this use, it is desirable to have a jack which 1s oompact andof small vertical height when lowered, in order to be placed under the low axle or other frame parts when the car .1s collapsed, and capable of a comparatively long lift to elevate the car above its normal driving height in order that the tire may be changed.

The jack is of that type employing a plu rality of screws telescoping one within the other and each contributing its share to the total lift of the jack. ,A continuous rotation of the driving means will cause thtl screws to be successively and individuallv elevated or lowered, one at a time. According to the embodiment of the invention here shown, two nested screws are emplo ed, the outer screw being an exteriorly tireaded sleeve which meshes within a nut formed in the rotatable driving gear, which is supported in a hollowwstandard. The inner lifting screw, which supports the load at its upper end, meshes within a nut formed in the upper end of the outer screw sleeve. In the operation of this ack, the .inner lifting screw will be held rom rotatxonby its engagement with the load. At this time, 1f the outer screw sleeve is held against rotation, it will be elevated through the rotatnu driving nut, carrying the inner screw an loud bodily upward with it. 0n the other hand, if the outer screw sleeve is permitted to rotate with the driving member, it will act as a nut to elevate the inner screw which carries the load.

This present invention is concerned more particularly with improvements in the means for controlling the rotary movements of the outer screw sleeve. The lower end of the sleeve is provided with projections which engage vertically extending ribs in the standard to hold the sleeve against rotation during its vertical travel, up or down, but these ribs terminate short of the upper and lower ends of the path of travel of the sleeve so that when at either of these ex- ,inafteln tremities of its vertical movement the sleeve may rotate freely. In the annular path of rotation of the projections on the sleeve, at both the upper and lower ends of the` standard, a spring stop device is provided which permits the free rotation of the projections 1n one direction, but prevents continued rotation thereof in the other direction. This stop device is in the form of a fiat spring strip which projects diagonally into the path of travel of the projections so that when a. projection is rotated in one direction it will push the spring strip out of its path and continue to rotate, but when rotated in the opposite direction, it will en gage the end of the spring and be held from urther rotary movement. This will force the screw sleeve to move vertically through the driving member, and after the projection has moved beyond the spring, 1t will, after a short angular movement, come into engagement with one of the` vertical guide ribs in the standard which prevents further rotation of the sleeve during its vertical travel through the standard.

The general object of the invention is to provide a jack o rating as brieiy noted above and as set orth in more detail here- Another object is to provide novel means for permitting rotation of the outer screw sleeve in one direction, when' at the upper limit of its travel, and in the opposite direction when at the lower limit of its travel, while preventing rotation of this screw sleeve at all other times.

Another object is to provide a novel spring stop device for insuring the proper reengagement of the projections on the sleeve with the guide ribs in the standard, when direction of movement of the lifting members is reversed.

Other objects and advantages of the invention will be readily apparent from the following detailed description of certain approved forms of the apparatus.

In the accompanying drawings:

Fig. 1 is a central vertical section through the jack, showing the outer screw at the upper limit of its travel, and the inner screw partially elevated.

, Fig. 2 is a horizontal section, on a somewhat larger scale, taken substantially on the line 2 2 of Fig. 1.

Figs. 3, 4 and 5 are sectional views, similar to Fig. 2, showing alternative forms of the spring stop mechanism.

Referring iirst to Fi s. l and 2, the stationary standard for t e jack comprises a substantially cylindrical hollow casting l,

rotatable nut 8 which is formed integral with the hub of driving beveled gear 9. A4

short stub shaft 10, journaled in an extension 11 of the housing 4, carries at its inner end a driving beveled pinion 12, which meshes with the beveled driving gear 9. The outer end of shaft 10 is provided with a socket 13 to cooperate with any suitable form of removable handle, whereby the jack may be operated from a. distance. It wi l be noted thatthe shaft 10 tilts upwardl so that the operators end of the handle wi l be elevated to a convenient position.

Since the driving nut 8 supports the lifting screws (hereinafer described) which in turn support the load the entire load will always be transmitted to the standard 1 through the anti-friction bearing 6, and in this Way the lifting or driving strain will be reduced to a minimum.

The outer screw 14 is in the form of a hollow sleeve exteriorly threaded to engage within the drivin nut 8. Pins 15 and 16, inserted between t e threads of screw 14 at suitable pxoints, or other equivalent means, engage t e bottom and to faces, respectively, of nut 8 to limit tie upward and downward travel of the outer screw 14. An inner screw 17 threaded in the same direction as screw 14, engages within a nut. 18 formed in the upper en of the screw sleeve 14. A load-supporting cap 19, preferably provided with an upper roughened load-engaging surface 20, is mounted upon the upper end of inner screw 17.

A pin of screw sleeve 14, and the projecting ends 22 of this pin-are adapted to engave with the vertical guide ribs 23, preferably cast integral with standard 1 and 'projecting into the vertical cylindrical bore thereof. A sin le rib 23 and projection 22 would be sucient, but it is preerable to have two dia-metrically opposed sets, as here shown. The ribs 23 terminate short of the u per and lower ends of the path of travel o `the pin 21 so that when the projections 22 have passed beyond theends of the ribs;Y the pin 21 and sleeve 14 can rotate freely within the annular spaces 24 and 25 provided in the respective ends of the standard for that purpose. In the specific forms of the invenange 3, while the. ot er member l of the raceway supports the 21. is secured through the lower end.

tion shown in Figs. 1, 2 and 3, the portions 24 and 25 of the cylindrical bore of the standard are made somewhat larger, or of greater diameter, than the main central portion of the bore so as to provide annular grooves for the reception of the spring members hereinafter described.

In the form of the invention shown in Figs. 1 and 2, a strip of Hat spring material 26 bent into substantially annular form, is housed within the upper enlargement 24 of the bore of the standard. One end portion of this spring strip extends diagonally inward, as at 2T, into the path of rotation of the projections 22, and is then bent radially outward, as at 28, the end of he strip extending through an aperture 29 in the wall of the standard. The opposite end 30 of the spring strip 26 is bent outwardly into the aperture 29 to lock the annular sprin against rotation, within the housing 24. t will be noted in Fig. 2 that as the pin 21 rotates in a counterclockwise direction, as indicated by the arrow, the projections 22 will successively engage the diagonal portion 2T of the spring and push it outwardly as indicated in dotted lines, the radial end portion 28 extending out at this time through the aperture 29. When the projection 22 has passed by, the spring will snap back to its solid line position. Therefore, the spring device will not interfere with the continuous rotary movement of the projections 22 and sleeve 14 in this direction. However, it' the direction of rotation is reversed so that the projections 22 move in a clockwise direction, as seen in Fig. 2, one of the projections 22 will engage the radial portion 28 of the spring, and further rotation of the sleeve 14 in this direction will be prevented.

A slightly modified form of spring is shown in Fig. 3. One end portion 32 of this spring extends diagonally into the path of rotation of the projections 22 similarly to the portion 27 of the first described modification, but the radial portion 28 of the spring is omitted. The o posite end of the annular spring is punchei outwardly, as at 33, into an opening 34 in the wall of the standard to hold the spring device against rotation. The operation of this modified form is substantially the same as that of the form first described. When the projections 22 are rotated in a clockwise direction, one of them will engage the end 35 of the spring 32 and be held against further rotation. In the modification shown in Fig. 4, a short spring 36, corresponding to the portion 32 of the spring shown in'Fig. 3, as its outer end 3 anchored by means of rivets 38 or similar devices, in an enlar ement or recess 39 at one side of the stan ard. The spring member 40, shown in Fi 5,'is similar to the spring 36 shown in ig. 4, with the exception that one end 41 of this spring extends outwardly through an opening 42 in the wall of the standard, und is anchored to the stainlard by screws 43 or equivalent devices.

A spring device exactly similar to any one of the forms hereinabove described is located within the annular space 25 at the lower end of the standard,'but this spring device is reversed, that is, extends in the opposite direction to those shown in Figs. 2 to 5, respectively. The reason for this will be apparent from the description of the operation which follows.

Now describing the general o eration of' the jack, we will first assume t iat the operating crank is beingl rotated in a clockwise direction and that the lifting screws have started upward to elevate the load. At this time the inner screw 17 will be completely housed within the outer screw sleeve 14, and since the driving nut 8 is rotatin in a counter-clockwise direction, as seen rom above, it will tendto rotate the screw sleeve 14 in the same direction. However, the projecting ends 22 of (pin 21 will engage the ribs 23 (as indicate in dotted lines in Fi 2) and further rotation of' the sleeve 14 wi l be prevented. Thereafter the rotation of nut- 8 will cause the screw 14 to be elevated therethrough, carr ing bodily n ward with it the inner screw 1i and the loa supported thereby. When the sleeve 14 has reached the upper limit of its travel, and the pin 15 has engaged against the lower side of nut 8, the projection 22 will have passed above the upper ends of the ribs 23 (as shown in Fig. 1), and are now permitted to rotate freely in a counter-clockwise direction, the nut 8 and sleeve 14 rotating as a unit. The projections 22 will successively engage the diagonal portion 27 of the spring stop mechanism, but will merely push this spring out of their path, as indicated in dotted lines at the lower portion of Fig. 2. Since the inner screw 17 is held from rotation by the load supported thereon, the rotating nut 18 in the upper end of sleeve 14 will cause the inner screw and the load to be elevated, until the stop pin 45 in the lower end of screw 17 engages the lower end of nut 18, thus preventing complete disengagement of the two screws.

In order to lower the jack, the operating crank is rotated in the opposite or counterclockwise direction. This will cause the driving nut 8 to be rotated in a clockwise direction` as seen from above, or as seen in Figs. 2 to 5, respectively. A partial rotation of the pin 21 will bring one of the rejecting ends 22 into engagement with tiie abrupt end 28 or 35 of the spring, thus preventing further rotation of the rojections `in this direction, and consequently prohibiting further rotation of the sleeve 14 in unison with nut 8. This will cause the sleeve to be lowered through the rotating nut until the projection22 has passed beneath the end of the stop spring. The sleeve 14 and pin 21 will now make a partial rotation, until the projet-ting ends 22 of gageinent with the guide ribs 23 which again prevent further rotation of the sleeve. The sleeve 14 will now be lowered through the standard until the projecting ends 22 of pin 21 have passed beyond the lower ends of the ribs 23 into the annular recess 25. The sleeve 14 will now be permitted to rotate with the driving nut 8, in a clockwise direction, thereby lowering the inner screw 17 into the screw sleeve so long as this screw 17 is held from rotation by the load thereon, or by any other means. As noted hereinabove, the spring detcnt or stop device which is located in the lower recess 25 is disposed oppositely to the one illustrated in Fig. 2 so that the pin 21 may rotate freely in a clockwise direction, but is prevented from rotating in a counterclockwise direction. When the direction of rotation of the operating crank is again reversed, so as to elevate the jack, this spring 26 in the lower recess 25 will function to prevent rotation of the pin 21 and sleeve 14 in a counter-clockwise direction until the sleeve has moved up far enough for the projections 22 to engage with the ribs 23, after which the operation is as first described hercinabove.'

A jack of this double screw type might be operated, under favorable conditions, if the spring detents which form the particular subject matter of this invention were omitted. In such case, however, there would be no certainty as to the respective order ot' movements of the two screws, either of which might go up or down first, according to the friction between the different parts. The sleeve 14 might start to move vertically at any time, and there is always the possibility that the projections 22 will 'am against thc upper or lower ends of the ri s 225, thus locking the parts and preventing further operation of the jack. The spring top devices` iusure a definite order of movements, compelling the screw sleeve 14 to move up or down first in either direction, and furlher more thespring stops are so located that the pin 21 and projections 22 will be stopped when out of vertical alignment with the ribs 23, thereby avoiding any possibility of jamming and consequent disabling ot the pick. These spring devices are simple and easy to manufacture and install, and Ido not appreciably increase the bulk of the jack. The springs used in the upper and lower ends of the jack standard are' identical in construction, being merely installed in reversed positions at the two ends of the jack.

The invention claimed in this application is limited to a lifting jack comprising the novel spring means herein disclosed for conthe pin have come into entrolling the rotation of the outer screw sleeve, or such modifications thereof as come within the scope of the tollowin claims. This type of jack is more broadl c aimed in the copending applications of alker et. al., Serial No. 740,958, filed October ll, 1924 for lifting jack; and Johnson, for screw jack, Serial No. 750,231, filed November 17, 1924.

I claim: j d' 1. In a lifting jack comprising a standard and a member `rotatable therein, means for controlling the rotation of this member com.-

prising a projection on the member, and a'.

spring strip secured to the standard and extending diagonally into the path of rotation of the projection.

2. In a lifting jack com rising a standard and a member rotatable t erein, means for controlling the rotation of this member comprising a projection on the member, and an annular spring strip mounted in the standard and having a portion extending diagonally into the path of rotation of the projection so that it will be pushed" aside when the projection rotates in one direction but will prevent rotation of the projection in the opposite direction.

3. In a lifting jack com rising a standard and a lifting member capa le of either vertical or rotary movements in the standard, means for controlling the movements of the lifting member, comprising a projection on the member, a substantially vertca the rojection to prevent rotation of the mem er, and a spring strip secured to the standard beyond the end of the rib out of vertical alignment therewith and extending diagonally into the path of rotation of the projection to permit rotation of the projection and member in one direction only.

4. In a lifting jack com rising a standard and a lifting member capa le of either vertical or rotary movements in the standard, be

means for controlling the movements ofthe lifting member, comprising a projection on the member, a substantially vertical guide rib in the standard adapted to be engaged by the rojection to prevent rotation of the member, and au annular spring strip mounted in the standard and having a portion extending diagonally into the path of rotation of the projection so that it will be pushed aside when the projection rotates in one direction but will prevent rotation of the projection in the opposite direction.

5. In a lifting jack, a hollow standard, and lifting mechanism supported by the standard and including a screw movable nism for controlling the rotation of the screw comprising a pro'ection on the screw, a substantially vertica giide rib in the standard, the projection ing adapted` to guide rib\ `in the standard, adapted to be engaged by 6. In a lifting jack, a hollow standard,`

and lifting mechanism supported b the standard `and including a screw movab e vertically through the standard, and mechanism for controlling thefrotation of the screw comprising a projection on the screw, a substantially vertical guide rib in the standard, the projection being adapted to move vertically beyond the end of the rib ,at which time it may rotate freely in one direction, and a. spring strip secured at one end to the standard and projecting diagonally into the path of rotation of the projection, the strip yielding to permit the projection to passin one direction, but the free end of the strip engaging the projection to prevent continued rotation in the other direction.

f 7. In a lifting jack, a hollow standard,

vertically through the standard, and mecha.-`

and lifting mechanism supported by the standard and including a screw movableA vertically through the standard, and mechanism for controlling the rotation of the screw comprising a projection on the screw, a substantially vertica uide rib in the standard, the projection ing adapted to move vertically beyond the end of the rib at which time it may rotate "freely in`one direction, and an annular spring member mounted in the standard about the path of 4rotation of the projection and having a portion projecting diagonally into the path -of the projection.

8. In a liftingjack, a hollow standard, a rotatable driving member, a pair of telescoping lifting screws, the outer screw being threaded withinlthe rotatable driving memr, a projection at the lower end of the outer screw, a guide within the standard for engaging the projection and preventing continued rotation of the screw while moving vertically, the guide terminatin short of one end of the kstandard where y the screw may rotate in one direction when the projection has passed beyond the guide, and means to stop rotation of the projection in the opposite direction when ont of vertical alignment with the guide comprising a flat spring projecting diagonally into the path of rotation of the projection.

9. In a lifting jack, a hollow standard a rotatable driving member, a pair of te e- *scoping lifting screws, the outer screw being threaded within the rotatable drivin member, a projection at the lower end o the outer screw, a guide within the standard for enga ing the projection and preventing continue rotation of the screw while mov- .izo

and projecting diagonally into the path of rotation of the projection. 10. In a lifting jack, a hollow standard, a'

rotatable driving member, a pair of telescoping lifting screws, the outer screw being threaded within the rotatable driving member, a projection at the lower end of the outer screw, a guide within the standard for engaging the projection and preventing continued rotation of the screw' While moving vertically, the guide terminating short of'one end' of the standard whereby the screw may rotate in one direction when the projection has passed beyond the guide, and means to stop rotation of the projection in the opposite direction when ont of vertical alignment with the guide comprising an annular spring member mounted in the standard about the path of rotation of the projection and having a portion projecting diagonally into the path of the projection.

11. In a lifting jack, a hollow standard, a rotatable driving member mounted in the standard, -a pair of telescoping lifting screws, the outer screw being` threaded within the rotatable driving member, a lateral projection on the lower end of the outer screw, a substantially vertical guide rib in the standard engaged by the projection when moving vertically, the rib terminating short of one endl of the standard whereby the projection may pass beyond the rib and rotate yfreely in one direction, the bore of the standard being formed with an annular channel beyond the end of the rib, and an annular Spring member mounted in this channel and having a portion projecting into the path of rotation of the projection, this spring portion being formedwith one diagonal face whereby the projection will push the spring member out of its path when rotated in one direction, and one abrupt face for stopping rotation of the projection in the opposite direction.

GLEN F. MCCAUGHEY.

ing vertically, the guide terminating short of one end of the standard whereby the screw may rotate in one direction when the projection has passed beyond the guide, and means to stop rotation ofthe projection in the opposite direction when out of vertical alignmentl with the guide comprising a fiat spring secured at one end to the standard and projecting diagonally into the path of rotation of the projection. a

10. In a lifting jack, a hollow standard, a rotatable driving member, a pair of telescoping lifting screws, the outer screw being threaded within the rotatable driving member, a projection at the lower end of the outer screw, a guide within the standard for engaging the projection and preventing continued rotation of the screw while moving vertically, the guide termin'ating short of one end' of the standard whereby the screw may rotate in one direction when the projection has passed beyond the guide, and means to stop rotation of the projection in the opposite direction when out of vertical alignment with the guide comprising an annular spring member mounted in the standard about the'path of rotation of the projection and having a portion projecting diagonally into the path of the projection.

11. In a lifting jack, a hollow standard, a rotatable driving member mounted' in the standard, Va pair of telescoping lifting screws, the outer screw being threaded within the rotatable driving member, a lateral projection on the lower end of the outer screw, a substantially vertical guide rib in the standard engaged by the projection when moving vertically, the rib terminating short of one endA of the standard whereby the projection may pass beyond the rib and rotate freely in one direction, the bore of the standard being formed with an annular channel beyond the end of the rib, and an annular spring member mounted in this channel and having a portion projecting into the path of rotation of the projection, this spring.,r portion being formed with one diagonal face whereby the projection will push the spring member out of its path when rotated in one direction, and one abrupt ace for stopping rotation of the projection in the opposite direction.

GLEN F. MCCAUGHEY.

CERTIFICATE OF CORRECTION.

Patent No. 1,653, 720.

Granted December 27, 1927, to

GLEN r. MCCAUGHEY.

` the word "he", read "the"; page 3,

Page 2, line 8l, for "top" "stopl':

the Patent Office.

Signed and sealed this 31st day of January, A. D. 1928.

Seal.

M. J. Moore,

s in the printed specification of the these corrections therein Acting Commissioner of Patents.

CERTIFICATE OF CORRECTION.

Patent No. 1,653,720. Granted December 27, 1927, to

GLEN r. MCCAUGHEY.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, Iine 8l, for

- the word "he" read "the"; page 3, line 112, for the word "top" read "stop";

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 31st day of January, A. D. 1928.

M. J. Moore,

Seal. Acting Commissioner of Patents. 

